The invention concerns a hydrodynamic clutch. The hydrodynamic clutch is of the type having an essentially horizontal axis, specifically for underground operation. A primary wheel is seated on a drive shaft, and a secondary wheel is seated on an output shaft. A housing comprises two essentially axially perpendicular end walls and, relative to the clutch axis, an essentially concentric peripheral wall. A scoop bowl is fastened to the primary wheel, forming a scooping space, and revolving jointly with the primary wheel. Outlet bores discharge from the working space into the scooping space, and a scooping pipe dips into the scooping space.
Such a clutch is known from the German utility patent 7,913,100. On this clutch, the housing comprises in its lower part a collection container for an operating fluid sump, additionally an upright container into which fluid from the sump is pumped, and lastly a splash disk which dips into the sump and lifts the fluid to the level of the collection container.
Clutches of this type may be either regulated or unregulated. Presently, they predominantly concern applications in underground operations. Here, the clutch is generally operated with water representing the operating fluid, frequently pit water.
Outlet bores are provided on the inside and outside diameters of the working circuit, so as to constantly release from the working space a certain amount of the operating fluid, i.e., of the water, and to circulate it for cooling purposes. These outlet orifices empty into a concomitantly rotating scooping space, or discharge into the clutch housing. The scooping space, i.e., the space between primary wheel and scooping bowl, is emptied by a scooping pipe, which then feeds the discharged operating fluid into a return system.
However, the operating fluid does not only accumulate in the scooping space. A sump is formed also outside the scooping bowl, between the outer peripheral surface of the scooping bowl and the inside surface of the peripheral wall of the housing where leakage fluid accumulates. Removal of this leakage fluid is critical for the following reasons: in view of the space constrictions underground, it is naturally desired to keep the outer dimensions of the clutch housing as small as possible. Therefore, also the gap space between the outside surface of the scooping bowl and the inner peripheral surface of the housing is small. Thus, there is no room for the arrangement of pumps or pump type units. Nonetheless, removal of the leakage fluid must be ensured, since during operation--due to rotor leakage or overflow--operating fluid constantly flows into the housing.
The problem underlying the invention is to so design a clutch such that the leakage fluid between scooping bowl and housing will be removed reliably, with little construction expense, and without appreciable energy losses.